<form action="/course_msgs/add_media" method="post" enctype="multipart/form-data" >
       <p>选择上传的图片: <br/>       
        <input style="width:180px;" value="选择上传的图片" type="file" name="media" class="file" style="padding:5px 10px;" /></p>
       <p><input value="上传文件" name="up" type="submit" class="button" style="padding:2px 8px;" /></p>
       
      <input type="hidden" name="cate_id" value="3">
      <input type="hidden" name="course_id" value="0">
      <input type="hidden" name="voice_length" value="30">
</form>